Electric switch



J. D. HILLIA'RD ELECTRIC SWITCH Filed Nov. 2o, 1922 z sheets-sheet 1Inventor vdsk-nrw D. Hilliawc;

if His Attorhe5- April 28, 1925.

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Illlll//llllllll J. D. HILLIARD 1,535'835 ELECTRIC A SWITCH Filed Nov.20, 1922 2 Sheets-Sheet 2 Fi .2..

l: E 'O' Inventor xiZDMilliavci b5 His Attorvwe.

Patented Apr. 28, 1925.

vUNITED STATES PATENT OFFICE. I

JOHN D. HILLIARD, OF SCHENECTADY, NEW YORK, ASSIGNOR GENERAL ELECTIt-ICCOMPANY, A CORPORATION OF NEW YORK.

lEmaocrnrc SWITCH.

Application led November 20, 1922. Serial No. 601,956.

To all whom 'it may concern:

Be it known that I, JOHN D. HILLIARD, a citizen of the United States,residing at Schenectady, in the county of Schenectady, v 5

State of New York, have invented certain new and useful Improvements inElectric Switches, of which the following is a speciication.

My invention relates to electric switches, and especially to means foraccelerating the openingof such'switches, and for preventing theiraccidental closure by pressure generated within the switch tank uponseparation of the switch contacts.

My invention is particularly useful in connection with switches operatedunder high pressure by an operating 'rod movable in- 'wardly through thetank wall -to separate the switch contacts. lIn the operation of suchswitches, difficulty has been encoun` tered by reason of piston actionof the operating rod tending to force it outwardly and thus toaccidentally close the contacts immediately after they have opened.

It is, therefore, a principal object of my invention to provide animproved means for utilizing the internal pressure of the switch to holdthe switch open until the arc incident to separation of the contacts hasbeen extinguished and normal pressure within lthe tank has beenrestored.

It is a further object to provide means by which the pressure within theswitch tank below the oil line may be utilized to accelerate the openingmovement of the switch.v

Other objects and advantages will appear as my invention is consideredin connection with the accompanying drawings in which Fig. 1 illustratesmy invention as appliedv to a single pole switch, and in which Fig. 2shows it as applied to a modified form of switch.

Referring now to Fig. 1, there is shown a supporting frame 1, attachedto the support 2, andl forming a part of the tank cover 3 which isprovided with` apertures for receiving the insulating bushings 4 and thecontact operating rod 5. The tank 6 is provided with an insulatinglining 7 and is adapted .to contain an insulating liquid 8. The bushings4 are designed to support the stationary electrodes 9 and are held inplace by the clamping rings 10. The contact operating rod 5 which entersthetank 6 through a packed'busliing 11 is adapted to support a movablebridging contact 12 which engages -the stationary contact members 9 tooperate the switch.

'.lhe operating means not shown but which may be of any suita le type,such as that shown in Letters Patent No. 942,491 to Emmet & Hewlett,dated December 7, 1909 for example) is connected to the link l 13,motion being transmitted to the operating rod 14 through the toggle15-16 and the operating lever 14.

A cylinder 17 is attached to the tank 6, registering apertures in eachbeing provided to form a communicating passage 18 which 1s protected byan insulating bushing 19. A hydraulically packed piston 20 is adapted tooperate in the cylinder 17 its downward movement being limited by thestud 21. A rod 22 is pivoted at 23 to one end of the bell crank lever 24and is guided in the piston casing by the spider 25.

Fig. 2 shows a switch of the explosion chamber type, the frame, tank andoperating mechanism of which is similar to that .shown vin Fig. 1. Anexplosion chamber casing 26 is attached to the stationary contact stud27 an extension of which forms a guide 28' for a piston 29 adapted tomove inside the explosion chamber casing 26. rlfhe piston is adapted tosupport contact lingers 30 which engage in the closed position of theswitch shown with a movable contact stud 31. Electrical connectionbetween the explosion chamber casing 26 and the piston 29 ismaintainedby a flexible lead 32. The inner side walls of the piston and the bottomof the explosion chamber casing are protected by an insulating lining33. The movable contact stud enters the explosion chamber through theinsulating bushing 34.

A rocker arm is pivoted to the explosion chamber 26 at 37 and isactuated by the pin 38 in the piston 29, transmitting motion of thepiston 29 to a connecting member 39 which may be made in the form of arod of insulating material or of metal rods connected to an insulator39.. The connecting member 39 is adapted to engage a pin 23 in the bellcrank 24 to complete the connection between the piston 29 and the'follows; The 4link 13 is moved to the left,

by 'any suitable operating means, to break the toggle 1.5-16 and permitdownward movement ofy the operating rod which disengages the movableelectrode 12 from thev contact fingers 9. Simultaneously with thedownward movement of the operating rod 5,

the rod 22 is raisedV parting contact with the piston 20. Uponseparation of the switch contacts an .arc is drawn inv the liquid whichvaporizes ordisassociates a part of the liquid ambient, the arc streamVthereby suddenly generating a pressure within the` switch tank. Thispressure is transmitted through the liquid to the piston 20 which isforced against the end of the rod 22 thereby serving to accelerate theopening movement of thel switch, the movable contacts of which arecooperatively associated with the rod 22 through bell crank lever 24,the toggle 15--16, the-operating lever 14 and the operating rod 5.Pressure will exist within the ytank until the arc is ruptured andduring thisl time reclosure of the switch due to piston action on theoperating rod 5 will be prevented by reason of the force exerted on thetoggle m'ember '16 through the retarding rod 22.

After the arc has been ruptured, normal pressure in the tank will berestored 'by` leakage and the switch may be reclosed, the piston 20being returned to the position shown by downward movement of the rod 22.

Operation under load from the closed position o'f'the switch shown inFig. 2 is as follows: Manual or automatic tripping of the operatingmeans permits the breaking of the toggle 15-16, the bell crank 24 movingin a counterclockwise direction. The operating rod 5 will fall to causedisengagement of the movable electrodes 31 from the contact lingers 30.lAn arc is drawn in the liquid which will cause the vaporization anddissociation of part of the liquid ambient the arc stream. A pressurewill be suddenly generated in the liquid in the explosion chamber whichwill produce upward movement of the piston 29 and the contact fingers 30to accelerate the relative movement between the Contact fingers 30 andthe movable contact 31. lfVhen the current to be interrupted is ofsufficient magnitude the pressure will be generated quickly enough sothe upward movement of the piston wil cause the connecting member 39 toovertake the pin 23 in the lll crank 24 inv its downward'movement,thereby pro-v ducing further 'acceleration of the movable contacts 31.-In any case, however, pressure will be exerted upon the piston 29until-the arc has been extinguished so that reclosure of the contacts istherebyprevented.

My invention may bev embodied in other forms than that shown anddescribed, and I therefore do not Awish to be lrestricted to the preciseconstruction shown, but intend to cover by the appended claims changesinvention.

What I claim Aas new and desire to secure electrodes, and a deviceresponsive to presl sure within vsaid -tank to prevent reclosure of saidelectrodes, said -electrodes being movable independently of said device.

4and modifications within the scope of my 2.'A switching apparatuscomprising la tank, contacts separable withinl said tank to break acircuit wherebyan arc is Jformed, means for operating saidelectrodes,and a device operated by pressurerwithin said'tank sol toassist in separating said .electrodes and -I- prevent their reclosure,said electrodes being movable independently of said device.

3. In a switching apparatus, a tank containinga liquid, electrodesseparable within said liquid to break a circuit whereby an arc is formedand pressure is created with- '.in 'said tank, means for operatingsaidelectrodes, a device responsive to pressure within said tank to assistlin separatingsaid electrodes and prevent their reclosure, and a lostmotion connection betwen said operating means and said device.

4. In a switching appara-tus,atank containing a liquid, electrodesseparable within said liquid tobreak a circuit whereby an arc is formedand pressure is created within said tank, means for operating saidelectrodes, a receptacle in communication -Wit-h said tank, and apistonwithinsaid receptacle responsive to pressure Within said tank toassist `in opening said electrodes and prevent their reclosure, saidelectrodes being movable independently of said' piston.

5. In a switching apparatus, a tank containing a liquid, electrodesseparable within said liquid to break a circuit whereby an arc is formedandA pressure is created within said tank, means for operating -saidelectrodes, a casing in communication with said tank beneath the surfaceof said liquid, a piston within said casing responsive to pressurewithin said tank to assist in opening saidelectrodes and preventl theirreclosure, and a lost motion connection between said piston and saidoperating means whereby said electrodes, maybe operated independently ofsaid piston.

6. In a switching apparatus, a tank conand Vmeans for transmitting athrust from taining an insulating llquid, electrodes relsaid piston tosaid operating means, said atively movable in said liquid to'make andlatter means permitting -the operation of 10 break a circuit, means foroperating said said contacts independently of said piston.

5 electrodes, a oylinder having a piston there- In witness whereof, Ihave hereunto setv in and having' a Huid connection with said my handthis 17th day of November, 1922. tank below the level of the liquidtherein JOHN D. HILLIARD.

